* { box-sizing: border-box; }

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, sans-serif;
    background: #fafafa;
    color: #1f2937;
}

header {
    background: #ffffff;
    border-bottom: 1px solid #e5e7eb;
    padding: 24px 40px;
}

header h1 {
    margin: 0;
    font-size: 22px;
    font-weight: 600;
    letter-spacing: 1px;
}

main {
    max-width: 1280px;
    margin: 40px auto;
    padding: 0 20px;
}

.intro {
    margin-bottom: 50px;
}

.intro h2 {
    font-size: 30px;
    font-weight: 500;
    margin-bottom: 16px;
}

.intro p {
    max-width: 760px;
    color: #4b5563;
    line-height: 1.7;
}

.category {
    margin-bottom: 60px;
}

.category h3 {
    font-size: 22px;
    font-weight: 500;
    margin-bottom: 25px;
    border-left: 4px solid #111827;
    padding-left: 12px;
}

.book-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 28px;
}

.book {
    background: #ffffff;
    border: 1px solid #e5e7eb;
    border-radius: 8px;
    padding: 18px;
    display: flex;
    flex-direction: column;
}

.book img {
    width: 100%;
    height: 300px;
    object-fit: cover;
    border-radius: 4px;
    margin-bottom: 14px;
}

.book h4 {
    font-size: 16px;
    font-weight: 500;
    margin: 0 0 10px;
}

.book p {
    font-size: 14px;
    color: #4b5563;
    line-height: 1.6;
    flex: 1;
}

.price {
    font-weight: 600;
    margin: 14px 0;
}

.book button {
    padding: 10px;
    background: #111827;
    color: #ffffff;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
}

.book button:hover {
    background: #374151;
}

.disclaimer {
    background: #f9fafb;
    border: 1px solid #e5e7eb;
    padding: 24px;
    margin-top: 60px;
    font-size: 13px;
    color: #6b7280;
    line-height: 1.7;
}

footer {
    border-top: 1px solid #e5e7eb;
    padding: 30px 20px;
    text-align: center;
    font-size: 13px;
    color: #6b7280;
}